Physics Commons^™

Polymeric Impulsive Actuation Mechanisms: Development, Characterization, And Modeling, Yongjin Kim

Doctoral Dissertations

Recent advances in the field of biomedical and life-sciences are increasingly demanding more life-like actuation with higher degrees of freedom in motion at small scales. Many researchers have developed various solutions to satisfy these emerging requirements. In many cases, new solutions are made possible with the development of novel polymeric actuators. Advances in polymeric actuation not only addressed problems concerning low degree of freedom in motion, large system size, and bio-incompatibility associated with conventional actuators, but also led to the discovery of novel applications, which were previously unattainable with conventional engineered systems. This dissertation focuses on developing novel actuation mechanisms …

Microextrusion 3d Printing Of Optical Waveguides And Microheaters, Edidiong Nseowo Udofia

Graduate Theses and Dissertations

The drive for smaller and more compact devices presents several challenges in materials and fabrication strategies. Although photolithography is a well-developed method for creating microdevices, the disparate requirements in fabrication strategies, material choices, equipment and process complexities have limited its applications. Microextrusion printing (μEP) provides a promising alternative for microfabrication. Compared to the traditional techniques, the attractions lie in the wide range of printable material choice, greater design freedom, fewer processing steps, lower cost for customized production, and the plurality of compatible substrates. However, while extrusion-based 3D printing processes have been successfully applied at the macroscale, this seeming simplicity belies …

Investigation Of Fundamental Principles Of Rigid Body Impact Mechanics, Khalid Alluhydan

Mechanical Engineering Research Theses and Dissertations

In impact mechanics, the collision between two or more bodies is a common, yet a very challenging problem. Producing analytical solutions that can predict the post-collision motion of the colliding bodies require consistent modeling of the dynamics of the colliding bodies. This dissertation presents a new method for solving the two and multibody impact problems that can be used to predict the post-collision motion of the colliding bodies. Also, we solve the rigid body collision problem of planar kinematic chains with multiple contacts with external surfaces.

In the first part of this dissertation, we study planar collisions of Balls and …

Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller

Graduate Theses and Dissertations

Materials with features at the nanoscale can provide unique mechanical properties and increased functionality when included as part of a nanocomposite. This dissertation utilizes computational methods at multiple scales, including molecular dynamics (MD) and density functional theory (DFT), and the coupled atomistic and discrete dislocation multiscale method (CADD), to predict the mechanical properties of nanocomposites possessing nanomaterials that are either 1-D (carbyne chains), 2-D (graphene sheets), or 3-D (Al/amorphous-Si core-shell nanorod).

The MD method is used to model Ni-graphene nanocomposites. The strength of a Ni-graphene nanocomposite is found to improve by increasing the gap between the graphene sheet and a …

Transferring Power Through A Magnetic Couple, Nickolas Cruz Villalobos Jr.

Senior Theses

Properties of several working magnetic coupled rotors have been measured and their performance compared to theoretical models. Axial magnetic couplers allow rotors to work within harsh environments, without the need for seals, proper alignment, or overload protection on a motor. The influence of geometrical parameters, such as distance from the center of the rotors, polarity arrangement, and the number of dipole pairs were experimentally tested. These results can be used to improve rotor designs, to increase strength and efficiency.

Analysis Of Dynamic Behaviour Of A Tensioned Carbon Nanotube In Thermal And Pressurized Environments, Ahmed Yinusa, Gbeminiyi Sobamowo

Karbala International Journal of Modern Science

In this paper, the dynamic behaviour of a tensioned single-walled carbon nanotubes (SWCNT) in thermal and pressurized environments is investigated analytically. With the applications of Bernoulli-Euler and thermal elasticity mechanics theories, the governing equation of motion are developed and solved using Laplace and Fourier transforms. The results of the close form solution in this work are in excellent agreements with past results in literature. From the parametric studies, it is established that as the magnitude of the pressure distribution at the surface increases, the deflection associated with the nanotube increases at any mode of vibration. However, a corresponding increase in …